Showing papers in "International Journal of Industrial Chemistry in 2013"

Corrosion problems during oil and gas production and its mitigation

Abstract: In order to ensure smooth and uninterrupted flow of oil and gas to the end users, it is imperative for the field operators, pipeline engineers, and designers to be corrosion conscious as the lines and their component fittings would undergo material degradations due to corrosion. This paper gives a comprehensive review of corrosion problems during oil and gas production and its mitigation. The chemistry of corrosion mechanism had been examined with the various types of corrosion and associated corroding agents in the oil and gas industry. Factors affecting each of the various forms of corrosion were also presented. Ways of mitigating this menace with current technology of low costs had been discussed. It was noticed that the principles of corrosion must be understood in order to effectively select materials and to design, fabricate, and utilize metal structures for the optimum economic life of facilities and safety in oil and gas operations. Also, oil and gas materials last longer when both inhibitors and protective coatings are used together than when only batch inhibition was used. However, it is recommended that consultations with process, operations, materials, and corrosion engineers are necessary in the fitness of things to save billions of dollars wasted on corrosion in the oil and gas industries.

Green synthesis of silver nanoparticles using carob leaf extract and its antibacterial activity

Abstract: Background This paper describes a rapid and eco-friendly method for green synthesis of silver nanoparticles from aqueous solution of silver nitrate using carob leaf extract (Ceratonia siliqua) in a single-pot process.

A review on the assessment of polymeric materials used as corrosion inhibitor of metals and alloys

Abstract: Corrosion control of metals is an important activity of technical, economical, environmental, and aesthetical importance. The use of inhibitors is one of the best options of protecting metals and alloys against corrosion. The toxicity of organic and inorganic corrosion inhibitors to the environment has prompted the search for safer corrosion inhibitors such as green corrosion inhibitors as other more environmental friendly corrosion inhibitors, most of which are biodegradable and do not contain heavy metals or other toxic compounds. Investigations of corrosion-inhibiting abilities of polymeric substances, e.g., plant gums, in addition to being environmentally friendly and ecologically acceptable, have shown that plant products are inexpensive, readily available, and renewable sources of materials. Need for more effective inhibitors has propelled companies such as the Montazhkhimzashchita Trust to develop a pool method of welding sheet vinyl, a method widely employed in gluing on roller sticky bands from thermoplast on a pipe. The article enumerates several kinds of polymeric materials which are suitable for use in combating corrosion, and several which have suitable strength characteristics as to serve in place of scarce expensive metals and alloys.

Focus on potential environmental issues on plastic world towards a sustainable plastic recycling in developing countries

Abstract: Due to the tremendous growth of plastics in the world, it has brought about environmental concerns for over the past two or three decades. Most of these plastics, due to poor management, are currently disposed of in unauthorized dumping sites or burned uncontrollably in the fields. The paper outlines environmental concerns of so many applications of plastics. The most important mechanisms of degradation of plastics, environmental impacts and recommendations for sustainable development are fully discoursed, with recycling option being overviewed as the route under most intense development at this time because of its broad public appeal and obvious environmental advantages.

Experimental evaluation of engine oil properties containing copper oxide nanoparticles as a nanoadditive

Abstract: Background The properties of lubricants are mainly the result of adding a material for improving or producing the required properties. Today, different materials with various nanostructures are used as new additives which, because of their unique properties, are used for improving the lubricant's properties. The purpose of the present research is to add copper oxide (CuO) nanoparticles to engine oil and evaluate the produced changes in some of its properties. Also, viscosity, pour point, and flash point of nanolubricants, which are made at different concentrations (0.1, 0.2, and 0.5 wt.%), and also their thermal conductivity coefficient as four quality parameters which are effective in the functionality of engine oil are evaluated.

Removal of Fe(II) from aqueous solution using pomegranate peel carbon: equilibrium and kinetic studies

Abstract: Background Pomegranate peel carbon was tested for its ability to adsorb iron(II) ions from solutions with alterations in the parameters such as pH, contact time, sorbent weight, metal concentration, and temperature.

Process optimization studies of Congo red dye adsorption onto cashew nut shell using response surface methodology

Abstract: Background High cost of commercially available activated carbon increases the treatment cost. Hence, no-cost or low-cost, alternate adsorbents are the current thirst in this area of research. The limitations of conventional methods of experimentation can mislead the optimum operating conditions. The present investigation mainly deals with utilization of the low-cost, agricultural waste adsorbent, cashew nut shell, and the determination of the optimum conditions for Congo red dye removal from an aqueous solution using response surface central composite design methodology.

Decolorization of organic dye solution by ozonation; Optimization with response surface methodology

Abstract: Background: Ozone was used as a strong oxidant for decolorization of solution containing organic dyes. Three azo dyes, CI acid black 1 (AB1), CI acid yellow 19 (AY19) and CI acid orange 7 (AO7) which are widely used colorants in leather dyeing and finishing processes, were quantified with colorimetry. The effects of influential parameters including the ozone dosage, initial concentration of the dyes, initial pH of the solution, and temperature on the decolorization efficiency were studied. Central composite design (CCD) was applied to the optimization of decolorization of the dye solution by ozonation, and a second-order polynomial equation was proposed to predict the process efficiency. Results and discussion: Predicted results were found to be in good agreement with experimental values (R 2 = 0.9365, 0.9643, and 0.9296 for AB1, AY19, and AO7 respectively), which proves the suitability of the model employed and the success of CCD in optimizing the conditions of ozonation process. The variation of process efficiency as a function of independent variables was shown by graphical response surfaces. Conclusions: It was found that response surface methodology could effectively predict and optimize the performance of ozonation process for decolorization of solution containing organic dyes, AB1, AY19, and AO7. Also, the optimum values of the process variables to achieve the maximum decolorization efficiency could be calculated and verified experimentally.

Equilibrium and kinetic studies of cadmium(II) and lead(II) ions biosorption onto Ficus carcia leaves

Abstract: Background: Ficus carcia leaves (fig leaves) for the removal of cadmium(II) and lead(II) ions from aqueous solutions have been investigated. Results: The biosorption of cadmium(II) and lead(II) ions was found to be dependent on the solution pH, initial metal ion concentrations, biosorbent dose, contact time, and temperature. The experimental equilibrium biosorption data were analyzed by two widely used two parameters, Langmuir and Freundlich isotherm models. Conclusions: Langmuir isotherm model provided a better fit with the experimental data than Freundlich model by high correlation coefficients R 2 . Kinetic studies showed that pseudo-second-order described the biosorption

Kinetics of the Fischer-Tropsch synthesis on silica-supported cobalt-cerium catalyst

Abstract: The process of converting synthesis gas into liquid fuels (Fischer-Tropsch synthesis) is a well-known technology. Among all Fischer-Tropsch synthesis (FTS) catalysts, Co- and Fe-based ones are applicable for industrial processes due to their low cost and high activity and selectivity. In this experimental study, a kinetic model has been developed for FTS reactions using co-precipitation technique and Co-Ce/SiO2 as the catalyst. Rate data have been obtained for CO hydrogenation over a co-precipitated well-characterized Co-Ce/SiO2 catalyst, studied in a fixed-bed micro-reactor at atmospheric pressure under the conditions of 200°C to 300°C, H2/CO feed ratio (mol/mol) of 1 and 1.5, and space velocity in the range 2,700 to 5,200 h−1. Characterization of both precursor and calcined catalysts was carried out using powder X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller surface area measurements. The kinetic parameters were estimated with nonlinear regression method. The data were best fitted by a Langmuir-Hinshelwood-Hougen-Watson approach. The activation energy for the optimal kinetic model was determined to be 31.57 kJ mol−1.

Micelles, mixed micelles, and applications of polyoxypropylene (PPO)-polyoxyethylene (PEO)-polyoxypropylene (PPO) triblock polymers

Abstract: This review gives a brief outline of various micellar properties of triblock polymers such as critical micellization concentration, critical micellization temperature, and microviscosity. Detailed discussion of the effect of temperature on micellar properties of various triblock polymer mixtures is given. Applications of triblock polymers in solubilization as drug delivery agents, as nano drug, for the synthesis of gold nanoparticles, for cobalt determination, etc. are discussed.

Proximate analysis, rheological properties and technological applications of some Nigerian coals

Abstract: Nigeria is endowed with large coal deposits, but some of them are yet to be explored. A combination of proximate analysis and rheological properties were used in characterizing the newly discovered Tai, Garin Maiganga and Shankodi-Jangwa coals in order to determine their suitable applications.

Removal of Cd(II) ion from wastewater by adsorption onto treated old newspaper: kinetic modeling and isotherm studies

Abstract: Background: This paper studied the ability of using treated old newspaper (TNP) as synthetic adsorbent for the removal of Cd(II) from aqueous solutions by batch operation. Various operating parameters such as pH, initial metal ion concentration, adsorbent dosage, and equilibrium contact time have been studied. Results: The results indicated that the adsorption of Cd(II) increased with the increasing pH, and the optimum solution pH for the adsorption of Cd(II) was found to be 6.4. Adsorption was rapid and occurred within 15 min for Cd(II) concentration range from 5 to 30 mg/L. Conclusions: The kinetic process of Cd(II) adsorption onto TNP was found to fit the pseudo-second-order model. The equilibrium adsorption data for Cd(II) were better fitted to the Langmuir adsorption isotherm model.

Optical properties of pure and modified poly(vinyl chloride)

Abstract: Background In this study, poly(vinyl chloride) (PVC) is considered one of the most versatile plastics. It is the second largest manufactured resin by volume worldwide.

Synthesis of multicore phenol formaldehyde microcapsules and their application in polyurethane paint formulation for self-healing anticorrosive coating

Abstract: Background: This paper describes the microencapsulation of linseed oil along with drier and corrosion inhibitor in polyurethane coating. Results: Linseed oil along with drier and corrosion inhibitor was encapsulated in phenol formaldehyde microcapsules successfully by in situ polymerization process. These microcapsules were characterized by Fourier transform-infrared and nuclear magnetic resonance spectroscopies, and their surface morphology was studied by scanning electron microscopy. The particle size of the prepared microcapsules was estimated by optical microscopy and confirmed using a particle size analyzer. The self-healing properties as well as anticorrosive performance of encapsulated microcapsules were studied in polyurethane coating. Corrosion protection of coatings with microcapsules containing linseed oil, corrosion inhibitor, and drier was compared with pristine coating free from microcapsules. Conclusions: The cracks in the paint film could be successfully repaired by the release of linseed oil from microcapsules ruptured under stimulated mechanical action, while corrosion inhibitor plays an important role to prevent the corrosion in a scribed line region.

Corrosion inhibitive properties of some new isatin derivatives on corrosion of N80 steel in 15% HCl

Abstract: Background: The inhibition effect of two synthesized isatin compounds, namely 1-morpholinomethyl-3 (1-N-dithiooxamide)iminoisatin [MMTOI] and 1-diphenylaminomethyl-3(1-N-dithiooxamide)iminoisatin [PAMTOI], on the corrosion inhibition of N80 steel in 15% HCl solution was studied by polarization, alternating current impedance (electrochemical impedance spectroscopy), and weight loss measurements. The surface examination was carried out by scanning electron microscopy and Fourier transform infrared spectroscopy. Results: The compounds [PAMTOI] and [MMTOI] show the maximum of 91.2% and 84.3% inhibition efficiency, respectively, at 200-ppm concentration. Polarization curves revealed that the used inhibitors represent mixed-type inhibitors. Adsorption of used inhibitors led to a reduction in the double-layer capacitance and an increase in the charge transfer resistance. Conclusions: Results show that both inhibitors were effective inhibitors and their inhibition efficiency was significantly increased with increasing concentration. Adsorption of both compounds obeys the Langmuir adsorption isotherm.

Low-temperature preparation and physical characterization of doped BaCeO3 nanoparticles by chemical precipitation

Abstract: In this work, the nanoparticles of pure BaCe1−xM x O3−δ (where M = Gd or Sm and x = 0, 0.10, or 0.20) were synthesized by the simple chemical precipitation method. The prepared materials were calcined at 300°C, 450°C, and 600°C for 2 h each to obtain phase-pure compounds. The samples were characterized by thermogravimetry/differential thermal analysis (TGA/DTA), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDAX) analysis, Fourier transform infrared (FTIR), particle size analysis, and scanning electron microscopy. TGA/DTA results have shown that phase-pure BaCeO3 materials can be formed only above 500°C. The crystalline structure of parent and doped BaCeO3 was found to be orthorhombic. EDAX analysis has shown the atomic percentage of elements present in the Gd- and Sm-doped BaCeO3 samples. FTIR studies have shown the presence of Ce-O in doped BaCeO3 nanoparticles. Doped BaCeO3 may be used as an electrolyte for solid oxide fuel cell applications.

Pigeon pea (Cajanus cajan) pod as a novel eco-friendly biosorbent: a study on equilibrium and kinetics of Ni(II) biosorption

Abstract: Background: Pod of pigeon pea (Cajanus cajan) was used as a novel eco-friendly material to investigate its nickel binding efficiency. The influence of key physicochemical parameters such as contact time, initial metal ion concentration, adsorbent dosage, and pH on Ni(II) removal was studied. Optimum Ni(II) removal was obtained with a contact time of 45 min, pH of 8.0, and an adsorbent dose of 0.4. Results: The removal of Ni(II) decreased from 95% to 85% as the initial metal concentration increased from 20 to 100 mg L �1 . Under the optimal conditions selected, metal ion adsorption equilibrium was very well represented by the Freundlich isotherm model followed by the Langmuir isotherm and Temkin isotherm models. The adsorption process followed second-order kinetics, and the corresponding rate constants for initial Ni(II) concentration ranging from 20 to 100 mg L �1 were found to be 0.179 to 0.0035 g mg �1 min �1 . Various thermodynamic parameters such as standard enthalpy (ΔH°), standard entropy (ΔS°), and standard free energy (ΔG°) were evaluated to predict the nature of adsorption. Conclusions: The adsorbent prepared from the pod of pigeon pea appears to be a promising adsorbent for the removal of Ni(II) ions from aqueous solution. The study indicated that the pretreated adsorbent produced through chemical activation using NaOH is an effective material for the removal of Ni(II). Hence, the adsorbent prepared from the pigeon pea pod would be an economically useful tool and alternative to the commercially available activated carbon in the treatment of effluent containing Ni(II) ions.

Investigation of correlation between rheological properties of rubber compounds based on natural rubber/styrene-butadiene rubber with their thermal behaviors

Abstract: Rubber compounds are widely used in many applications because of the properties they exhibit. The physical and mechanical properties of these blends are sensitive to small variations in the amount of the individual polymers used. Thermogravimetry is currently gaining wide acceptance as a method for compositional analysis of vulcanizates. Knowledge of the relationship among thermal behavior of rubber compounds with their rheological properties is important for the assessment of the optimum process conditions to produce materials that have required properties. The correlation of rheological properties of rubber compounds based on natural rubber/styrene-butadiene rubber with their thermal behavior has been assessed using thermogravimetry analysis. Thermogravimetric method permits the analysis to be completed in a short time and requires only a small sample. Thermogravimetry derivative profile (DTG) of the uncured blends and their rheological properties were investigated. Differential derivative curves of uncured vulcanizate showed that the degradation of styrene-butadiene rubber takes place at a higher temperature than that of natural rubber. According to DTG curves, two useful factors were demonstrated. These factors were the peak height ratio of natural rubber/styrene-butadiene rubber and a new factor called ‘normalized factor ,’ which could be correlated with the rheological properties of the blends. The result showed that the rheological nature of samples had acceptable correlation with the factors obtained by thermal analysis method. In other words, in this work a simple and reproducible experimental method was developed to efficiently predict the rheological properties of rubber blends.

Synthesis and chemical modification of maleic anhydride copolymers with phthalimide groups

Abstract: Maleic anhydride (MAN) copolymers with methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate monomers at 1:1 mole ratios were synthesized by free radical polymerization in the presence of α,α′-azobis(isobutyronitrile) as initiator and dry ethyl acetate as solvent. Copolymer compositions were obtained using related proton nuclear magnetic resonance (1HNMR) spectra, and the polydispersity of the copolymers was determined by gel permeation chromatography. Then, a solution of phthalimide salt as a nucleophilic reagent reacted through the ring opening of anhydride groups in copolymers resulting to modified copolymers IPht to VPht. All the prepared polymers were characterized by Fourier transform infrared and 1H NMR spectroscopic techniques. The glass transition temperature (Tg) of all copolymers before and after modification was determined by dynamic mechanical thermal analysis (DMTA). It was shown that chemical modification of MAN copolymers with phthalimide substituents as side chains decreased the free volume of the polymers, and therefore, the rigidity and Tg are increased. Solubility of the copolymer products was tested in some organic solvents.

Effect of the ratio of catalyst to carbon source on the growth of vertically aligned carbon nanotubes on nanostructured porous silicon templates

Abstract: Background The effect of the ratio of catalyst to carbon source on the growth of vertically aligned carbon nanotubes (VACNTs) has been studied.

Rheological study of partially hydrolyzed polyacrylamide-hexamine-pyrocatechol gel system

Abstract: Background: The cross-linked polymer gels exhibit non-Newtonian rheological behavior which can be described well by the different types of rheological models. This study investigates the onset of gelation behavior of partially hydrolyzed polyacrylamide-hexamine-pyrocatechol polymer gel system which may be used to control excessive water production in the oil fields. Rheological measurements of this system have been performed at different time intervals and pH at 90°C. Attempts have been made to validate the onset of gelation behavior with Bingham plastic, Herschel-Bulkley, Mizrahi-Berk, and Robertson-Stiff model. Results: It was observed that the developed polymer gel system under the present study has better agreement with the Robertson-Stiff model. Conclusions: The viscosity of cross-linked polymer gel solution increases with temperature with the passage of time. This increased viscosity leads to gel formation which in turn behaves as flow diverting agent or blocking agent for controlling excessive water production in the oil fields.

Generation of PVP fibers by electrospinning in one-step process under high-pressure CO2

Abstract: Background: Electrospinning is a process of electrostatic fiber formation using electrical forces to produce polymer fibers from polymer solution in nano/micrometer scale diameters. Various polymers have been successfully electrospun into ultrafine particles and fibers in recent years, mostly in solvent solution and some in melt form. In this work, electrospinning was conducted under high-pressure carbon dioxide (CO2) to reduce the viscosity of polymer solution. The experiments were conducted at 313 K and approximately 8.0 MPa. Polyvinylpyrrolidone in dichloromethane was used as a polymer solution with 4 wt.% of concentration. The applied voltage was 17 kV, and the distance of nozzle and collector was 8 cm. The morphology and structure of the fibers produced were observed by scanning electron microscopy. Results: When the CO2 pressure was 5 MPa, the resultant fibers had an average diameter of 2.28 ± 0.38 to 4.93 ± 1.02 μm. The ribbon-like morphology was formed with increasing pressure of CO2 at 8 MPa with a tip 0.75-mm inside diameter. Conclusions: The results show that the depressurization of CO2 at the end of experiment assists the removal process of the polymer solvent and produces the porous nature of fibers without collapsing or foaming. These behaviors hold the potential to considerably improve devolatilization electrospinning processes.

Extraction and characterization of seed oil waxes by using chromatographic techniques

Abstract: Background The chemical composition of the crude waxes extracted from three different seed oils (sunflower, canola, and cottonseed) was studied using chromatographic techniques.

Kinetic modeling: a predictive tool for the adsorption of zinc ions onto calcium alginate beads

Abstract: The main purpose of this study is to develop a nonlinear model of a batch adsorption and to evaluate the model's capability in the prediction of experimental adsorption data. Additionally, results of the nonlinear model were compared with data of pseudo first- and second-order models. Experimental data were extracted from the adsorption of zinc ions using calcium alginate beads prepared via electrospray method. In order to study the effects of biosorbent porosity and the initial concentration of the zinc solution on adsorption kinetics, calcium alginate beads were prepared with two different porosities and zinc concentrations. The results revealed that the nonlinear model offers a much more accurate prediction compared with other models as the average root mean square deviation of the nonlinear model was calculated to be only 2.66%, which was smaller at least four times than that of others. Furthermore, the nonlinear model showed that diffusive transport through beads was limited by pore diffusion. The nonlinear model provided a good fit to the experimental data as the calculated equilibrium adsorptions were shown to be in good agreement with their experimental counterparts.

Synthesis and application of CNT-supported MoO3-K2O nanocatalyst using microemulsion technique: role of nanoparticle size on catalyst activity and selectivity in higher alcohol synthesis

Abstract: Background Alkalized MoO3 nanocatalyst supported on carbon nanotubes (CNTs) is prepared using microemulsion technique. The nanocatalyst was extensively characterized by different methods, and its activity and selectivity in higher alcohol synthesis (HAS) have been assessed in a fixed bed micro-reactor. The physico-chemical properties and performance of the nanocatalyst were compared with the catalyst prepared by impregnation method.

The effect of feldspar and kaolin on mechanical performance of SBR/LDPE composites

Abstract: Background Feldspar and kaolin was ball milled at 320 rpm for hours with the aid of a dry grinding agent. Both minerals were combined with inorganic salt namely sodium chloride as a grinding agent. The grinding agent and mineral were mixed at the ratio of 1:1.

DFT investigations on the interaction of oxygen reduction reaction intermediates with Au (100) and bimetallic Au/M (100) (M = Pt, Cu, and Fe) surfaces

Abstract: Background: Density functional theory was used to demonstrate how the presence of second metals can modify the adsorption energies of oxygen reduction intermediates on Au (100) surfaces. Taking the importance of the modification of oxygen reduction reaction in fuel cell activity into consideration, the adsorption energy and the stable adsorption sites for the intermediates of this reaction in Au (100) and bimetallic Au/M (100) (M=Pt, Cu, and Fe) systems were closely examined. After optimization of the structures, calculations of the density of states, d-band center, electron charge transfer, and adsorption energies of the intermediates of oxygen reduction reaction were accomplished. Results: The d-band center has been shown to be shifted because of strain and ligand effects in these bimetallic systems. The important role of hydroxyl species (OH) on catalytic surfaces was revealed while studying intermediates of oxygen reduction reaction. Hydroxyl species are strongly adsorbed on the catalytic surfaces and decrease the kinetic of oxygen reduction reaction by occupying the active adsorption sites. Conclusions: Au-Pt-Au (100) has the biggest OH adsorption energy. Therefore, it can be concluded that the presence of the submonolayer of Pt in this bimetallic system has helped hydroxyl species occupy the active sites, and consequently, it is not an appropriate catalyst for oxygen reduction reaction.

Modeling of fluidized bed reactor for ethylene polymerization: effect of parameters on the single-pass ethylene conversion

Abstract: Background In this study, we present the developments in modeling gas-phase catalyzed olefin polymerization fluidized bed reactors (FBR) using chromium catalyst technique. The model is based on the two-phase theory of gas-solid fluidization: bubble phase and emulsion phase. The model has proved to be the suitable model in many of past studies. In the proposed model, the bed is divided into several sequential sections. The effect of important reactor parameters such as superficial gas velocity, catalyst injection rate, catalyst particle growth, and minimum fluidization velocity on the dynamic behavior of the FBR has been discussed. The conversion of product in a fluidized bed reactor is investigated and compared with the actual data from the plant site.

Removal of anionic dye from aqueous solution using a cationic carrier

Abstract: Background The transport of Cibacron Red FN-R (Sigma-Aldrich, MO, USA) anionic dye through a methylene chloride (Merck, India) bulk liquid membrane containing a tetrabutylammonium bromide (TBAB; Merck, India) as an excellent carrier was studied. The extracted dye simultaneously stripped into aqueous stripping solution.